Feet per Second to MPH Converter
Convert feet per second (ft/s) to miles per hour (mph) instantly. Type a value — the result updates as you type, and the swap button converts the other way.
ft/s to mph formula
mph = ft/s × 0.6818181818
1 foot per second = 0.6818 miles per hour · 1 mile per hour = 1.47 feet per second
To convert feet per second to miles per hour, multiply the value by 0.6818181818. For example, 100 ft/s:
mph = 100 × 0.6818181818mph = 68.181818
So 100 ft/s = 68.18 mph.
Mental math shortcut
Quick mental estimate: multiply by 2/3. For 100 ft/s that gives about 66.67 mph — off by 1.52 mph (2.2%). Use the exact formula when precision matters.
ft/s to mph conversion table
mph back to ft/s
The same values converted the other way, rounded for everyday use:
| Miles per hour | Feet per second |
|---|---|
| 0.6818 mph | 1 ft/s |
| 6.82 mph | 10 ft/s |
| 15 mph | 22 ft/s |
| 30 mph | 44 ft/s |
| 60 mph | 88 ft/s |
| 68.18 mph | 100 ft/s |
| 340.91 mph | 500 ft/s |
| 681.82 mph | 1000 ft/s |
About the units
Feet per second (ft/s)
Feet per second is a speed unit used in ballistics, engineering and sports. 1 ft/s ≈ 0.68 mph.
Miles per hour (mph)
Miles per hour is the speed unit used on roads in the US and UK.
Frequently asked questions
How many miles per hour are in a foot per second?
One foot per second equals 0.6818 miles per hour.
What is 100 ft/s in mph?
100 ft/s = 68.18 mph.
How do I convert mph back to ft/s?
Divide the miles per hour by 0.6818181818.